Many therapeutic spa tubs or swimming pools employ complex piping systems for the injection of water and air inside the tub area. The injection of water and air may be at such impact velocities as to be too harsh for the occupant. Conventional spas employ a plurality of high pressure jets distributed about the inner periphery of the spa shell, normally beneath a seat. The presence of venturi nozzles add air to create a bubbling stream of water for soothing the body of the occupant of the spa. Typically, the occupant must move to limit the length of time of an area of the body in direct contact with the bubbling streams of water. To effect massaging of the user's back, it is necessary for the occupant to lower or raise himself in the spa to vary the jet contact area on the back or other portion of the user's body.
It is therefore a primary object of the present invention to provide an improved hydrotherapy seat structure for a hydrotherapy spa at one or more predefined areas of a waterproof spa shell to create a plurality of small size water jets emanating from the back and seat area of the spa shell for low velocity impact against the back and buttocks of the occupant of the hydrotherapy seat, which may be effected at low cost and in which the impact velocity is limited to thereby prevent that velocity from being too harsh for the occupant of the hydrotherapy seat.